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' J. B. PENTZ.

METHOD 0E STERILIZING SURGICAL INSTRUMENTS AND OTHER ARTICLES.

l* APPLICATION FILED MAR. 4,19l5. 3193779725 Patentd May MP9 19231.

` v *t 2 SHEETS-SHEET I.

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METHOD 0F STERILIZING SURGICAL INSTRUMENTS AND OTHER ARTICLES.

APPLICATION FILED MARMI, ISII5.

Iimf, Patented May III, 1921.

2 SHEETS-SHEET 2.

JAMES BOLTON PENTZ, OF NEW YORK, N. Y.

METHOD'OF STERILIZING SURGICAL INSTRUMENTS AND OTHER ARTICLES.

Specication of Letters Patent.4

Patented May 1U?, 1921i..

Application led March 4, 1915. Serial No. 11,951.

To all w from if may oon-cern Be it known that I, JAMES BOLTON PENTZ, acitizen of the United States, residing at New York, county of Richmond,and State of N ew York, have invented certain new and usefulImprovements in Methods of Sterilizing Surgical Instruments and otherArticles, of which the following is a full,

. clear, and exact description.

Experience with, and careful study of, practically all known methods ofsterilization for a considerable period have led me to the conclusion,shared by many other surgeons and bacteriologists, that there is greatneed of a method which shall be unfailingly perfect in its results butwhich will at the same time be quick and convenient to use. To this endI have devised my present invention, which has for its chief object toprovide a method which shall be practically instantaneous in its effectsand yet render the instrument or appliance sterile in the true sense ofthe word. A further object is to provide a method which can be practisedby means of simple and durable apparatus of low cost. To these and otherends the invention consists in the novel method and features hereinafterdescribed.

In practising my invention in the preferred manner the instruments orother articles to be sterilized are subjected, in the presence of vapor,to a temperature high above the boiling point of the liquid from whichthe vapor is produced, the heating of the article being effected in avessel or container which is not hermetically sealed but is open to theatmosphere for the escape of theI steam, or vapor, as the case may be,so that the pressure within the container or chamber will bel butlittle, if any, above atmospheric. Heretofore, subjecting theinstrument, in the presence of steam, to a temperature above the boilingpoint of water at` atmospheric pressure has always implied the use of a.closed receptacle and a pressure therein corresponding to thetemperature. It is well known that, however effectual such a proceduremay be, it is slow, at times requiring hours for the attainment ofperfect results. Why this is so I am not able to explain with certainty,but the fact remains. On the contrary, in the use of my method the timeof complete sterilization is counted by seconds instead of minutes orhours, and in fact the time ishusually so short-five or six seconds oreven less, depending generally upon the temperature employed`that themethod for all practical purposes can be called instantaneous.

he apparatus which I prefer to use for performing the process isillustrated in the accompanying drawing, in which- 'Figure 1 shows thecomplete device in longitudinal vertical section.

Fig. 2 is a cross section on line 2 2 of Fig. 1.

F 3 is a detail side view of the inner heating element, the outerprotective casing being in section.

Fig. is a side view, partly in longitudinal section, of a modificationof the sterilizer shown in Fig. 1.

Fig. 5 is a side view, of a` liquid reservoir sterilizer.

The outer casing is preferably cylindrical in form and mounted in aslightly inclined position on a support-ing base 11. The inner heatingelement is in the form of a chamber 12 preferably elliptical in crosssection, provided at one end with a head 13 and near the other with aradial flange or collar 14 to support the chamber cenrally in the casing10 and spaced from the walls thereof. Removable caps 15, 16, of conicalform, are provided for the ends of the casing and are fastened againstaccidental displacement by means of binding bolts 17, 18. Each cap isformed with a central aperture, that in cap 15 being provided for theelectrical connections hereafter described and that in cap 1.6 to permitinsertion and withdrawal of the drawer or cage 19.

In the present apparatus the heat is produced preferably by the iow ofcurrent through a resistance wire wound around the chamber 12, butinsulated therefrom by means of insulating strips 21, of porcelain orother suitable material arranged longitudinally on the chamber and heldin place by wires or bands 22, the insulating strips or bars beingserrated, as shown, to receive the wire 20 and insure proper spacing ofits turns. Notches 12a in the strips 21 next to the chamber 12 permitsurplus water, discharged oii the top of the chamber as hereafterdescribed. to run freely down the sides of the chamber. The terminals ofthe heating element pass through insulating tubes or bushings 23, 24,into electrical conpartly broken away, for use with either head 13.Connection with a source of current is made by means of a socket 26.Preferably the socket is overlapped by the edge cap 15, as shown in Fig.1, to prevent accidental unscrewing of the socket as the plug (notshown) at the other end of the cord 27 is screwed into its socket.Removing the cap 15 will of course permit removal of the socket 2G.

On the casing 10 is a reservoir 23 for the liquid u sed (by preferenceordinary water) having a sight feed 29' through which the water isdelivered onto the heating element. A needle valve 30, threaded in atubular support 31, controls the flow of water so that the delivery maybe drop-by-drop at any desired rate. The lid 32 is merely dropped on thereservoir, and may be removed instantly for cleaning or filling thereservoir. In the bottom and sides of the chamber I provide a number ofapertures 33 to permit free ingress of steam into the chamber.

The tray or drawer 19 is foraminous, preferably throughout its entirelength, though for convenience the perforations or apertures are shownonly at the ends. It is usually semi-elliptical in cross section, butenough smaller than the chamber 12 to leave a space between the two, atleast at the bottom, as clearly shown in Figs. 1 and 2, to permit freeaccess of the steam. On the outer end of the tray or drawer is a cap 34of the aperture in the having a flange 35 engaging at severalpoints theprojecting end of the chamber 12 and thereby aiding in supporting thetray inside the latter. It is not intended, nor is it even desirable, inthe absence of a steam escape opening elsewhere, that the cap make aclose fit with the chamber-end, and in fact the chief object ofproviding the cap and flange is to deflect escaping steam radiallyoutward and so protect the hand more effectually when the handle 36 isgrasped to insert or remove the drawer. The escape of steam around thecap 34 or through an escape opening elsewhere, insures a pressure in thesterilizer but little, if any, above atmospheric during sterilization.

In practising my method in the preferred manner with the apparatusdescribed, the current is turned on and the reservoir supplied withwater. In a few minutes, depending on the strength of the current, thesize and nature of wire 20, etc., the chamber 12 becomes highly heated,inside and out, say to a temperature of from 200O to 300O C. The valve30 is now opened and the water thus allowed to issue, preferably drop bydrop. The heat generated by the heating element vaporizes the water, andthe steam thus produced passes into the interior of the sterilizingchamber 12 through the openings 33 in the walls thereof. The

tray 19 with the non-sterile instruments or other articles lying loosetherein, is now inserted into the chamber 12 (if not already in thechamber), thus exposing the contents of the tray to the heat radiatedfrom the hot walls of the chamber and to heat carried to said contentsby the steam. How long the instruments should be left in the traydepends largely upon the temperature in side the sterilizer. Forexample, instruments bearing large quantities of typhoid bacilli wererendered completely sterile in six seconds, when the temperature wasabout 2930 C., in ten seconds at 275o C., and in fifteen seconds at2350-2500 C. I amnot aware that results comparable to these have everbeen attained with any practical h eatprocess of sterilizationheretofore known.

Upon removing the tray, moisture in the form of a film or in drops isusually found on the instruments, but the latter speedily dry of theirown heat. Moreover, they usually cool quicklyy to a safe handlingtemperature for the reason that seldom if ever do they attain, exceptpossibly at their surfaces, the temperature to which they were subjectedin the sterilizing chamber. This is shown by the fact that with thesterilizer running at its maximum temperature a thermometer placedtherein required 26 seconds to reach 150o 200O C., 1 minute and 3seconds to reach 250O C., 1 minute and 25 seconds to reach 275o C., and2 minutes and 23 seconds to reach 300O C. It is not necessary to insert'the tray far enough to close the sterilizing chamber, but if the tray isno llonger than necessary to accommodate the instruments the latter mayproject out of the chamber if the tray is not pushed home; in which casethe parts that project say an inch or more may not be completelysterilized, though the parts well inside the chamber will be madeperfectly sterile.

I am not able to explain to my complete satisfaction just why the methoddescribed is so effective, since it contravenes the previously acceptedtheories that would apply. But the fact remains that the process isdemonstrably superior in cihciency and convenience to boiling or baking,and to the use of steam under high pressure and at a correspondingtemperature. f

Water and steam are referred to herein as the most convenient for thepurpose, and in fact I know of none better, but other liquids may beused; and it is within the spirit of my invention to use an aqueoussolution of a volatilizable germicide, but I have not observed that anybetter results are obtained thereby. I also prefer to generate the steamor other vapor by discharging a liquid upon or into the heatedsterilizing chamber, or at least into the outer casing, but thegeneration can be effected at a more C., 40 seconds to reach remotepoint and the vapor conveyed to the sterilizing chamber through suitablepipes.

The sterilizer shown in Fig. 4 dilfers from that shown in Fig. 1practically only in respect to the heating element. The latter, in Fig.4, comprises a sheet metal tube or chamber covered with a layer ofrefractory insulating material, preferably mica or mica-composition, onwhich the resistance wire 4l is mounted, as by winding the samehelically thereon. The heat thus generated heats the tube 40 and thewater or other liquid is delivered to the-inside of the same through theshort tube 42 at the top from any suitable reservoir, for example onelike that shown in Fig. l or that shown in Fig. 5. In the latter, whichis formed at the bot-- tom to screw on the nipple 43, the needle valveis omitted and the central tube 44 is imperforate at the bottom and openat the top. Slidable vertically on this tube is a cup 45 attached to thebottom of a tubular stem 46 capable of vertical movement on said centraltube and having drain apertures 47 at the bottom. A spring 48,encircling the tube 44 holds the cup and stem yieldingly in their upperposition, against the flared upper end of the aforesaid tube. water isto be delivered to the sterilizer the stem is pressed down, carrying thecup down into the reservoir 49, causing the cup to receive watertherefrom. Upon re- .lease of the stem the cup is raised to the positionshown in Fiof. 5, carrying with it a quantity of liquid, w ich runs outthrough the drain openings 47 into the tube 44 and thence through thenozzle 50 into the sterilizer. This method of liquid-supply eliminatestrouble due to leaky valves and consequent iooding of the sterilizer,since only a limited quant-ity of liquid is delivered at 1 eachactuation of the measuring cup. A

drain tube 51, Fig. 4, permits immediate escape of any excess liquidfrom the sterilizer.

It is not necesary that the articles to be sterilized be heated beforethey are placed in the sterilizer. It is more convenient and isapparently quite as effective to introduce them at whatever temperaturethey may happen to have, which is usually ordlnary room 4 temperature.

It is to be understood that the invention is not limited to theapparatus herein specifically illustrated, but can be practised by meansof other devices of Widely varying character.

ll claim:

l. The herein described method-of sterilizing which consists insubjecting the article to be sterilized to a temperature above the Whenboiling point of water, in the presence of steam at substantiallyamospheric pressure. 2. The herein described method of sterillzing,which consists of `heating to a temperature exceeding the boiling pointof water, a chamber containing the article to be sterilized, andintroducing steam at substantially atmospheric pressure into the chamberand into contact with the article.

3. The herein described method lof Sterilizing, which consists ininclosing the article to be sterilized in a chamber having a temperaturehigh above the boiling point of water and containing steam atsubstantially atmospheric pressure.

4. The herein described method of sterilizing, which consists insubjecting the article to be sterilized to an atmosphere containingsteam at a temperature exceeding the boiling point of water and atsubstantlally atmospherc pressure.

5. The herein described method Vof sterilizing, which consists inpreparing an atmosphere having a temperature 'exceeding that of boilingwater, supplying steam at substantially atmospheric pressure to saidatmosphere whereby the temperature of the steam is increased, andintroducing the article to be sterilized into said atmosphere in arelatively cold state.

6. The herein described method of sterilizing, which consists insubjecting the article to be sterilized, in a relatively cold state, tosteam at a temperature above the boiling point of water and atsubstantially atmospheric pressure.

7 The herein described method of sterilizing, which consists insubjecting the article to be sterilized to heat radiated from the wallsof a chamber heated to a temperature exceeding the boiling point ofwater and to steam at substantially atmospheric pressure.

8. The 4herein described method of sterilizing, which consists insubjecting the article vto high temperature radiated heat and at thesame time to steam at substantially atmospheric pressure.

9. 'llhe herein described method of sterilizing, which consists ininclosing the article to be sterilized in a chamber having walls heatedto a temperature high above the boiling point of water, whereby thearticle is heated by radiation, and containing Isteam at substanitallyatmospheric pressure.

In testimony whereof l aHiX my signature in the presence of twosubscribing witnesses.

JAMES BOLTON PENTZ.

Witnesses:

N. LAWSON Dime, S. S. DURHAM.

